Indicating apparatus



Jan. 26, 1943. A. E. DODD 2,309,174

A INDICATING APPARATUS Filed NOV. 23, 1940 EW H n 7?,

I n Il l g'g INVENTOR Apzzwodd- MAQ/W IHS 'ATTORNEY Patented Jan. 26,1943 UNITED STATES PATENT OFFICE INDICATING APPARATUS of PennsylvaniaApplication November 23, 1940, Serial No. 366,791

Claims.

My invention relates to indication apparatus, and particularly toapparatus of the type disclosed in United States Patent No. 2,168,805,issued August 8, 1939, to John M. Pelikan, and assigned to The UnionSwitch and Signal Company.

In some situations it is desirable to provide two types of indicationsof a change in a condition. For example, in a tower where railwaysignals are controlled it is desirable on entrance of a train into atrack section to provide a momentary audible indication, and to alsoprovide a visual indication, such as a light, which is continued as longas the track section is occupied.

In such installations there are usually several track sections occupancyof which is to be indicated, and it is desired in these situations toemploy one single stroke bell to provide the audible indication onoccupancy of any one of the various track sections, and to provide aseparate lamp to supply the visual indication for each track section.

It is desired to arrange the equipment so that on entrance of a traininto any track section the bell is operated to provide an audiblesignal, yand so that the lamp for that section is lighted. It is desiredalso that the equipment for each track section be arranged so as not tointerfere with that of the other track sections, and so that when atrack section is vacated the equipment associated with that section willbe conditioned for operation on subsequent occupation of the tracksection.

It is an object of this invention to provide improved means adapted foruse in the manner described above.

A further object of the invention is to provide a system of the typedescribed which requires only a single front contact of a relay toprovide the proper control of both the audible and the visual signal.

A further object of the invention is to provide a system of the typedescribed having a bell relay and a plurality of condensers whichprovide means to momentarily energize the bell relay, and having theequipment arranged so that only a single contact is required on eachcontrol relay to control both charging and discharging of a condenserand resultant operation of the bell relay. u

Another object of the invention is to provide a system of the typedescribed and having the equipment arranged in such manner thatregardlessof the number of condensers and control relays which areassociated with one bell relay, each condenser will be effective tocause momentary operation of the bell relay, and so that the condenserswill not detract from the effectiveness of each other.

A further object of the invention is to provide improved indicationmeans.

Other objects of the invention and features of novelty will be apparentfrom the following description taken in connection with the accompanyingdrawing.

I shall describe two illustrative embodiments of my invention and shallthen point out the novel eatures thereof in claims.

In the accompanying drawing,

Fig. l is a diagram showing one form of indication means provided by myinvention, and,

Fig. 2 is a diagram showing another form of indication means which I mayemploy.

Similar reference characters refer to similar parts in each of the twoviews.

Referring to Fig. 1 of the drawing, there are shown therein controlrelays ITP, ZTP and STP each of which is controlled by a condition, suchas occupancy of a section of railroad track, not shown. Each of theserelays is normally deenergized, and is energized on occupancy of theassociated track section. The circuits of these relays are not shown,and the relays may be controlled in any manner Well-known in the art.

Each control relay has associated therewith an electroresponsive device,here shown as a lamp L, for providing one indication, while otherelectroresponsive means, here shown as a single stroke bell yGcontrolled by an auxiliary relay GR,

is provided to give a second indication.

Each of the control relays has associated therewith a condenser TC' fromwhich energy is supplied to the relay GR as hereinafter explained, whilethe condensers have rectiiiers or asymmetric units RX and RY associatedtherewith so that the condensers do not interfere with each other.

The equipment is shown in the drawing in the condition which it assumeswhen the various track sections are vacant. At this time the ccntrolrelays TP are released and the circuits of the lamps L are interrupted,while the relay GR is released to interrupt the circuit of the bell G.

In addition, at this time the condensers TC are charged from a source ofdirect current the terminals of which are designated -land The circuitfor charging the condenser ITC is traced from the positive terminal ofthe source through the rectier IRX to one plate of the condenser, whilethe other plate of the condenser is connected through the lament of lampIL to the negative terminal of the source. There is no flow of currentin this circuit after the condenser becomes fully charged andaccordingly the lamp is not lighted. The condensers 2TC and STC arecharged by current supplied over similar circuits.

When a train enters a track section, as for example that with whichrelay ITP is associated the Contact I5 of relay ITP closes andestablishes a circuit to supply energy from the source to the lamp ILand also establishes a circuit to supply energy from the condenser ITCto the relay GR. The circuit for energizing the lamp IL is obvious inthe drawing. The circuit for supplying energy from the condenser ITC tothe relay GR i5 traced from one element of the condenser through therectiiier IRY and wire I .to one terminal of the winding of relay GR,while the other terminal of the relay GR is conn-ected by wire I I andthe contact I of relay ITP to the other element of the condenser. Onestablishment of this circuit energy stored in the condenser ows throughthe winding of the relay GR so that the contact of this relay picks upand establishes the circuit of the bell G and the bell is operated toprovide a single audible signal of the fact that a track section hasbecome occupied.

The energy supplied from the condenser iTC to the relay GR soondecreases to a value insuiiicient to maintain the relay picked up andits contact releases and interrupts the circuit of the bell G so thatthe bell is conditioned for another operation.

As long as relay ITP remains picked up, the lamp IL continues to belighted to provide a visual indication of occupancy of the tracksection, but when the section becomes vacated relay ITP will release andwill interrupt the circuit of the lamp IL. In addition, release of relayITP will interrupt the connection from the positive terminal of thesource to the condenser ITC, and so the condenser will again be chargedover the circuit which includes the lamp IL in series therewith.

The operation of the equipment controlled by relays 2TP and 3TP is thesame as that controlled by relay ITP and a detailed description thereofis unnecessary.

The system provided by this invention is arranged so that if while onetrack section is occupied another becomes occupied the bell will ring toprovide an audible indication of occupancy of the second track section.

If for example the section associated with relay ITP is occupied so thatrelay ITP is picked up, and the section associated with relay ZTPbecomes occupied relay 2TP will pick up and its contact I5 willestablish the circuit to supply energy from the condenser 2TC to therelay GR so that this relay will pick up and supply energy to the bellG.

At this time the rectifier IRY serves to prevent flow of energy from thecondenser 2TC to the condenser ITC and accordingly all of the energyfrom the condenser 2TC is available to vpick up the relay GR. If therectier IRY were not provided energy from the condenser 2TC would besupplied to the condenser ITC over a circuit which is traced from oneelement of the condenser 2TC through wire I0 to one element of thecondenser ITC, while the other elements of these condensers areconnected vtogether through the contact I6 of relay 2TP, wire II andcontact I5 of relay ITP. The rectier IRY prevents ilow through wire I Ito an element of condenser ITC,

and thereby prevents charging of lthe condenser ITC from the condenser2TC at these times. II this flow oi energy from one condenser to anotherwere permitted to occur too little energy might be supplied to the relayGR to pick up the relay.

In like manner the rectiiiers 2RY and 3RY prevent charging of theassociated condensers from the other condensers.

The rectiers RX operate to prevent short cirl cuiting of the condenserson picking up of the control relays. If these rectiiiers were notprovided, on picking up of the contact of a control relay a circuitwould be established from the positively charged element of theassociated condenser through the relay contact to the other element ofthe condenser. The rectiers RX prevent iiow of energy in this directionand accordingly prevent this short circuiting of the condensers whichwould otherwise occur.

The system shown in Fig. 1 has normally charged condensers and employsenergy lfrom these condensers to energize the bell control relay. Thesystem shown in Fig. 2 is similar to that shown in Fig. 1 but differstherefrom in that it has normally uncharged condensers and employs thecurrent required to charge these condensers to energize the bell controlrelay.

The equipment shown in Fig. 2 is shown in the condition which it assumeswhen the various track sections are vacant. At this time the controlrelays TP are released, thereby interrupting the circuits of the lamps Land of the condensers TC, while the bell control relay GR is releasedand interrupts the circuit of the bell G.

If a train enters the track section associated with control relay ITP,contact I5 of this relay picks up and establishes the circuit of thelamp IL, and also establishes a circuit to charge the condenser ITC,this circuit including in series therewith the bell control relay GR.The circuit for lighting the lamp IL is obvious in the drawing. Thecircuit for charging the condenser ITC is traced from the positiveterminal of the source through the contact of relay ITP to one elementof the condenser ITC, while the other element of the condenser isconnected through the rectifier ITX to one terminal of the winding of`the relay GR, the other terminal of which is connected to the negativeterminal of the source. This other element of the condenser is alsoconnected to the negative terminal of the source through the rectifierITY.

Accordingly, on picking up of the contact of relay ITP the lamp IL islighted While the condenser ITC is charged over a circuit which includesthe relay GR in series therewith. As a result of the ow of energy in thecircuit for charging the condenser ITC the relay GR is energized and itscontact picks up and establishes the circuit of the bell G so that thebell provides an audible indication of the fact that a track sec tionhas become occupied. When the condenser ITC becomes charged the flow ofenergy in the circuit of the Winding of relay GR ceases and this relayreleases and interrupts the circuit of the bell G so that the bell isconditioned for another operation.

As long as the track section is occupied the relay ITP is picked up andits contact I5 establishes the circuit of the lamp IL so that the lampprovides a visual indication of the fact that the section is occupied.When the section is vacated the relay ITP releases andinterrupts thecircuit of the lamp IL and also interrupts the circuit for charging thecondenser ITC so that energy is no longer supplied to the condenser,while the energy stored in the condenser discharges through a circuitwhich is .traced from one terminal oi the condenser through the lamp IL,and thence through the rectiiier ITY to the other terminal of thecondenser. Accordingly the condenser ITC is discharged and isconditioned for a subsequent operation.

The equipment asociated with relays 2TP and STP operates in the samemanner as that associated with relay ITP and a detailed explanationthereof is unnecessary.

The system provided by this modication also operates sothat when onetrack section is occupied the bell will be operated if another sectionbecomes occupied.

When the section associated with relay ITP is occupied relay ITP ispicked up and the lamp IL is lighted, while the condenser I TC ischarged as it is connected across the source by a circuit which includesthe relay GR in series therewith.

Un subsequent picking up of contact I6 of .the relay ZTP the circuit ofthe lamp 2L is established, while the condenser 2TC is connected acrossthe source by a circuit which is traced from the positive terminal ofthe source through the Contact I of relay 2T?.D to one terminal of thecondenser, and from the other terminal of the condenser through therectier ZTX and the winding of relay GR to the negative .terminal of thesource. Accordingly, energy flows through the winding of relay GR andthis relay picks up and establishes the circuit of the bell G so thatthe bell provides an audible signal.

When the condenser becomes charged the flow of energy through thewinding of relay GR ceases andthe relay releases and interrupts thecircuit of the bell G.

As long as the track sections are occupied the relays ITP and ZTP arepicked up and the lamps IL and 2L are lighted while the condensers ITCand 2TC remain charged. When these sections are vacated the relays ITPand 2TP release and interrupt the circuits of the lamps and of thecondensers so .that the lamps are extinguished and the ccndensersdischarge as explained above.

The rectiers employed in the modification shown in 2 are arranged toinsure proper operation of the equipment under all conditions. The`rectiiier ITY is poled so as to permit the condenser ITC to dischargethrough the lamp IL on release of the relay ITP. This rectier is alsopoled so that on picking up of the relay ITP the energy to charge thecondenser must flow through the winding of relay GR so that this relaywill pick up.

Similarly the rectiers TX insure that all of the energy `for chargingeach of the condensers fiows through the winding of the relay GR and isnot supp-lied through the other condensers. If, for example, therectiers ZTX and BTX Were not provided a connection would be establishedfrom the negative side of the condenser ITC through condenser 2TC andlamp 2L to the negative terminal of the source, while a similarconnection would be established through condenser 3TC and lamp 3L, andon picking up of the relay ITP a portion at least of the energy forcharging the condenser ITC would be supplied over these connections andnot through the winding of relay GR. If this were permitted to occur theenergy supplied through the relay GR might be insufficient to pick upthe relay.

From the foregoing it will be seen that this invention provides animproved indication system which operates to provide a momentary audibleindication and a continuing visual indication, and also that the systemis arranged so that only a single contact on the control relay isrequired. In the systems shown in the drawing the circuits are arrangedso that each includes a front contact of a control relay so that theindications are provided when the control relays are picked up.Howevenit should be understood that these circuits might be arranged toinclude only a back contact of the control relays so that theindications are provided when the control relays are released.

The iact that the indication means provided by this inventionnecessitates the use of but a single contact on the control relay is adistinct advantage as these relays usually have a limited number ofcontacts and these contacts are required for other purposes.

In addition it will be seen that in each of the two modifications thereis a condenser and two electro-responsive devices, namely a lamp and theauxiliary relay, In each of the two modifications the condenser ischarged by energy supplied over a circuit including in series therewithone of the electroresponsive devices, while the condenser is dischargedover a circuit including the other of the two devices. In each of thetwo modincations one of these circuits has an asymmetric unit includedin series therewith to thereby insure iiow of current through theauxiliary relay on closing of the control relay contact, while .eachmodication also has asymmetric units included in the circuits of theauxiliary relay to prevent energy intended for this relay from beingdiverted to one of the condensers.

While the two modifications of the invention have been illustrated anddescribed as employing three control relays so that indications may beprovided for three track sections, it should be understood that either asmaller or a larger number of control relays may be employed ifindications for a different number of track sections are required.

Likewise, while the equipment has been described as providing means toindicate occupancy of a section of railroad track, it should beunderstood that the invention is not limited to use for this purpose,but may be employed wherever indication means of this type is desirable.

In addition, while the equipment has been illustrated and described asemploying a lamp to provide one form of indication and a bell to providea different form of indication, the invention is not limited to the useof these devices and any desired form of indication means may beemployed.

Similarly, while in the systems shown in the drawing, charging ordischarging of a condenser energizes an auxiliary relay which controlsthe circuit of the bell, the invention is not limited to thisarrangement, and it is contemplated that the auxiliary relay might beomitted and the bell energized directly from the condensers.

Although I have herein illustrated and described only two forms ofindication apparatus embodying my invention, it is understood thatvarious changes and modications may be made therein within the scope ofthe appended claims without departing from the spirit and scope of myinvention.v

Having thus described my invention, what I claim is:

1. In combination, a source of direct current,

nected across the terminals of said source, each circuit including inseries therewith a lamp and a normally open control contact, eachcircuit having associated therewith a condenser having one of itsterminals connected to said circuit at a point intermediate the lamp andthe control contact, each condenser having its other terminal connectedthrough an asymmetric unit to one terminal of said indication device andalso through another asymmetric unit to the other terminal of saidindication device, one of the assymmetric units associated with eachcircuit being arranged to permit energy to flow from the indicationdevice terminal to the condenser and the other asymmetric unitassociated with each circuit being arranged to permit energy to flowfrom the condenser terminal to the indication device terminal, and aconnection from one terminal of said source to one terminal of saidindication device, whereby when one of said control contacts is closedthe lamp associated with said control contact is lighted and a circuitincluding in series therewith the condenser and the indication device isestablished and the indication device is momentarily energized duringflow of current in such circuit.

2. In combination, a source of direct current, an indication device, aplurality of lamps each having its first terminal connected to oneterminal of said source and each having its second terminal connectedthrough a normally open control contact to the other terminal of thesource, a condenser associated with each lamp, each con denser havingone of its terminals connected to the second terminal of the associatedlamp, each condenser having its other terminal connected through a rstasymmetric unit to one terminal of the indication device and alsoconnected through a second asymmetric unit to the other terminal of saidindication device, one of said asymmetric units being poled to permitenergy to flow from the condenser to the indication device and the otherasymmetric unit being poled to permit energy to flow from the indicationdevice to the condenser, and a connection from one terminal of saidsource to one terminal of said indication device.

3. In combination, a source of direct current, a first indicationdevice, a plurality of second indication devices each having its firstterminal connected to one terminal of the source and having its secondterminal connected through a normally open control contact to the otherterminal of the source, each of said second indication devices havingassociated therewith a condenser having one of its terminals connectedto the second terminal of the associated second indication device, eachcondenser` having its other terminal connected through a firstasymmetric unit to one terminal of the first indication device and alsoto one terminal of the source, said other terminal of each condenseralso being connected through a second asymmetric unit to the otherterminal of the first indication device, one of said asymmetric unitsbeing' poled to permit energy to flow to the associated condenserterminal and the other of said asymmetric units being poled to permitenergy to flow from the associated condenser terminal.

4. In combination, a source of direct current, a

an indication device, a plurality of circuits con# first indicationdevice, a plurality of second indication devices each having its firstterminal connected to the negative terminal of the source and having itssecond terminal connected through a normally open control contact to thepositive terminal of the source, each of said second indication deviceshaving associated therewith a condenser having one of its terminalsconnected to the second terminal of the associated second indicationdevice, each condenser having its other terminal connected through afirst asymmetric unit to one terminal of the first indication device andalso to the positive terminal of the source, said other terminal of eachcondenser also being connected through a second asymmetric unit to theother terminal of said first indication device, each first asymmetricunit being poled to permit energy to flow to the condenser terminal,whereby the condenser is normally charged over a circuit which includessaid first asymmetric unit and the associated second indication devicein series therewith and whereby each condenser is prevented fromdischarging through the other condensers, each second asymmetric unitbeing poled to permit energy to flow from the condenser terminal,

` whereby on closure of the control Contact associated with saidcondenser the condenser may discharge through a circuit including inseries therewith the second asymmetric unit and the first indicationdevice, and on closure of another of said control contacts the condenserassociated with that contact is prevented from discharging through thecondenser with which said asymmetric unit is associated.

5. In combination, a source of direct current, a first indicationdevice, a plurality of second indication devices each having its firstterminal connected to the negative terminal of said source and havingits second terminal connected through a normally open control contact tothe positive terminal of the source, each of said second indicationdevices having associated therewith a condenser having one of itsterminals connected to the second terminal of the associated secondindication device, each condenser having its other terminal connectedthrough a rst asymmetric unit to the negative terminal ci the source andalso to one terminal of the first indication device, said other terminalof each condenser also being connected through a second asymmetric unitto the other terminal of said first indication device, each rstasymmetric unit being poled to permit energy to flow to the condenserterminal whereby energy stored in the condenser may discharge throughthe associated second indication device and said first asymmetric unitbut energy to charge said condenser is prevented from being supplied tothe condenser through the circuit including said first asymmetric unit,each second asymmetric unit being poled to permit energy to flow fromsaid condenser terminal, whereby on closure of the control contactassociated with said condenser the condenser is charged by energysupplied over the circuit which includes the first indication device inseries therewith and on closure of another of the control contactsenergy to charge the condenser associated With that contact is.prevented from being supplied through the condenser with which saidasymmetric unit is associated.

ARTHUR E. DODD.

